Tag: biomechanics

One Egyptologist isn’t ready to close the book on the tale of two toes. Once thought to be mere ornamentation for the afterlife, the artificial toes found on two ancient Egyptian mummies may actually be the earliest known prosthetic limbs.

The fake toes in question are the Greville Chester and Tabaketenmut toes. The Greville toe dates to before 600 BC and is made of cartonnage (similar to papier mâché); the Tabaketenmut toe could date as far back as 710 BC and is made mostly of wood, though researchers believe it also contains leather, and it even has a hinge for flexibility.

Jacky Finch, an Egyptologist at the University of Manchester, UK, had a hunch that these artificial toes weren’t just for looks. Not only were the toes rigorously correct in their anatomy, but they also showed signs of wear and tear–which prompted an experiment that has been over 2,000 years in the making.

Have you ever wondered why woodpeckers don’t pass out after scrounging a meal from a tree? Their little brains, after all, undergo decelerations of 1200g as they bang their beaks against the wood–over ten times the force needed to give a human a concussion. Now scientists are learning how to harness the woodpecker’s special abilities not to prevent headaches, but to safeguard our gadgets.

Researchers at the University of California, Berkeley, analyzed CT scans and video footage of the golden-fronted woodpecker (Melanerpes aurifons) to design better shock absorbers. They found that woodpeckers have four traits that ease their noggins: fluid between the skull and brain, a beak that is slightly elastic, a section of soft skull bone, and a bone called the hyoid, or lingual bone, which is also somewhat elastic.

The scientists then constructed a woodpecker-inspired shock-absorbing system around a circuit using materials that approximated the bird’s four absorbers. For example, rubber represented the supportive and slightly-elastic nature of the hyoid bone, while aluminum mimicked the brain-skull fluid. With the circuit securely surrounded, they stuffed it inside a bullet and fired the bullet at an aluminum wall using an air gun.

In pursuit of a glorious future in which robots can outrun humans (what could possibly go wrong?), researcher Ryuma Niiyama has unveiled Athlete, a bot that’s intended to sprint.

The bipedal robot’s upper legs are modeled on the human musculoskeletal system, while the lower legs are fashioned from the spring-like blades that amputee runners use (and use so effectively that some have called the blades an unfair advantage).

Each leg has seven sets of artificial muscles. The sets, each with one to six pneumatic actuators, correspond to muscles in the human body — gluteus maximus, adductor, hamstring, and so forth…. The researchers are now teaching Athlete to run. They programmed the robot to activate its artificial muscles with the same timing and pattern of a person’s muscles during running.

Niiyama described his bot at the IEEE conference on humanoid robots last week, and has published a paper (pdf) on the project in the journal Industrial Robot. The challenge is to get all those artificial muscles working in sequence as the bot bounds across the landscape.

It’s a big challenge. So far, Athlete can take only three to five steps before tumbling to the ground. Still that’s pretty impressive compared to a hopping prototype from 2007 (seen in the video below), which took one great leap for robotics and promptly fell down. Humans, maybe you don’t need to run for your lives just yet.

The gecko robot just keeps getting better. Not only can the robot climb up walls like the sticky-toed lizard, but it can automatically right itself while falling.

Geckos, like cats and buttered toast, can naturally turn themselves around in midair. Cats are able to right themselves because they are flexible and can twist their bodies around. The gecko, on the other hand, uses its large tail’s inertia to twist its body around to the correct orientation, explains Cosmic Log:

Within about a tenth of a second, the geckos flipped their tails around to induce body rotation. Then they spread out their tails as well as their feet into a “belly-down skydiving posture” position to stabilize the fall. All of the geckos that used their tails in this way landed on their feet, even in wind-tunnel tests–while none of the tailless geckos could do the same trick.

To find a mate, most animals must travel—up a tree, down a stream, across the street to the bar. But not barnacles, which spend their entire adult lives cemented firmly to rocks, boats, whales and the like. To compensate for their immobility, barnacles have evolved the longest penises relative to body size in the animal kingdom.

The appendages can reach up to ten times the length of the barnacles’ bodies to allow them to search of a partner. See a video—safe for work!—below.

According to new research published in Marine Biology, the shape of barnacles’ penises varies depending on their circumstances. Barnacles spaced far apart from each other develop stretchier organs, the better for reaching across the gaps, and barnacles exposed to rough waves grow wider ones to stand up against the tide.

“Many furry mammals engage in oscillatory shaking when wet.” Translation: When a dog comes in from the rain, it engages in a body-twisting, jowl-flapping shake that sprays water over the living room. But exactly what kinds of oscillations are required to make the water droplets scatter? Thankfully a team of curious researchers decided to study the physics of that motion.

In the abstract posted on ArXiv, Andrew Dickerson of the Georgia Institute of Technology and some colleagues explain that they attacked the question via high-speed video and fur-particle tracking:

After a presentation on “hydraulic leg extension” in large spiders and another on “aspects of octopedal locomotion,” researchers attending today’s Society for Experimental Biology annual meeting learned how to run like a three-legged dog.

Martin Gross of the University of Jena in Germany presented a project that could one day teach disabled planet-exploring robots how to keep trekking or damaged military robots how to survive the battlefield. Watching how his brother’s dog adapted to losing a leg, Gross was impressed with both the dog’s coping methods, and speed.

“The one with only three legs is still the fastest of all his dogs,” Gross told the BBC.

Briton Ged Galvin survived that vicious car wreck that nearly took his life. Unfortunately, the accident crushed some of his organs and left him needing a colostomy bag to go to the bathroom.

That was until his doctors created his cyborg sphincter. Yes, you read that correctly. Doctors removed muscle from above Galvin’s knee, wrapped it around his damaged sphincter, and attached electrodes to the nerves. Now, when Galvin goes to the bathroom he simply presses a button on a remote control.

Mr Galvin, who had previously endured the indignity of carrying a colostomy bag, added: “I thought that in these days of modern medicine surely there was something they could do. They’d mended everything else – why not this? Anything was better than a colostomy bag.

“The operation changed my life and gave me back my pride and confidence. Because of the remote control I can lead a normal life again.”

Outstanding. Though hopefully Galvin’s remote has a lock that prevents him from accidentally triggering it while it’s in his pocket.